Friday 12 October 2012 03.56 EDT
First published on Friday 12 October 2012 03.56 EDT

A former BBC TV director has claimed he blew the whistle about Jimmy Savile having sex with a young girl at the BBC but was ignored when he reported the incident to his bosses.

David Nicolson, now 67, worked with Savile on Jim'll Fix It and Top of the Pops over 10 years and said his bosses just shrugged it off when he told them what he had seen.

He said it is wrong of executives at the corporation to say nobody knew what was going on because "everyone would have known about it".

Nicolson claimed he walked into Savile's dressing room one day and caught him having sex with a "very, very young" girl in his dressing room.

"It was a bog standard changing room in the basement. They both quickly pulled up their pants. The girl could have been 16, maybe 15. But she was just one of many – he always had one in the room," Nicolson told the Sun. "He said 'What do you want, young man?' and shouted at me to get out of the room."

He added: "I was shocked. I had gone in to talk business and quickly got out."

When he reported the incident, he was told "That's Jimmy". "I was revolted by his behaviour. They just shrugged it off, saying 'Yeah, yeah – that's the way it goes.'"

Nicolson told the Sun: "Everyone knew what was going on. That includes senior BBC people – chiefs at the highest levels.

"There were always girls in Jimmy's dressing room. Everyone would have known about it – all the hair and makeup people, the wardrobe, show directors, producers."

He said on the set of Jim'll Fix It, Savile would always bring "scruffy girls into the studios – all teenagers. But no questions were ever asked."

A BBC spokesperson said: "We have been disturbed to hear these allegations. All staff past and present who have any information relating to allegations of this kind should raise them with the BBC's internal investigations unit or with the police directly."

The allegations against Savile are mounting by the day, with the National Association for People Abused in Childhood saying it had been "inundated with calls". Chief executive Pete Saunders said two former patients at Stoke Mandeville hospital had phoned the agency on Thursday to say that not only had they been abused by Savile but also by a doctor.

On Thursday claims were made by former patients at the rehabilitation hospital and the Leeds General Infirmary that Savile used his position as a charity worker there to prey on vulnerable children. One former patient at the Leeds hospital said she witnessed him molesting a brain-damaged girl. And the Guardian has been told of claims that he raped a victim at the Broadmoor high security psychiatric hospital.

Rob Wilson, a Tory MP and aide to the health secretary demanded an independent inquiry into Stoke Mandeville.

"There is some confusion [on Thursday] about the status of what the BBC is doing with regard to its internal review of the decision to drop its Newsnight investigation, he said. "But it still rather odd that, one day after announcing it would hold an 'independent' inquiry headed by an outsider, the BBC announces a separate internal inquiry/review into its decision to shelve a major report detailing Savile's sexual abuse crimes. Why have one internal investigation for one aspect of the corporation's conduct and an 'independent' inquiry for all the rest?"

Savile's former driver has claimed in the Daily Mirror that the presenter used to lure vulnerable girls as young as 12 during fundraising events at hospitals. The wife of Dennis Garbutt, who now suffers dementia, said her husband told her that Savile would say to him 'Go and get a cup of tea, Den' as a signal to leave him alone. "We both feel bad that we never said anything to the police," Lucy Garbutt said.

Meanwhile, the ITV team behind the Exposure documentary that first aired the claims against Savile says a fourth TV personality has been accused of abusing a young woman. "We have had a name given to use which is so far not in the public domain. It relates to a celebrity, a media personality, who is alive," ITV said in a statement. Mark Williams-Thomas, the child abuse expert who made the programme, confirmed that since it was aired he has also been approached about another celebrity.

• To contact the MediaGuardian news desk email editor@mediatheguardian.com or phone 020 3353 3857. For all other inquiries please call the main Guardian switchboard on 020 3353 2000. If you are writing a comment for publication, please mark clearly "for publication".

• To get the latest media news to your desktop or mobile, follow MediaGuardian on Twitter and Facebook

In the wake of the Jimmy Savile scandal, a TV producer, who wishes to remain anonymous, gives an account of an industry in which women must still tolerate innuendo and groping – and explains why they are afraid to challenge it